Manufacturers of liquid detergent compositions desire well-mixed products. However, commonly used mixing methods can lead to aerated compositions, where small air bubbles are present, at least temporarily, in the liquid detergent.
Aeration in liquid detergents can pose a variety of challenges to the manufacturer. For example, aeration can cause increased variability in manufacturing systems that rely on volume or density measurements. Such systems are common, for example, in automated filler systems, where portions of the composition are placed into containers, such as bottles that will be sold in a store. Additionally, aeration in externally structured product can lead to product instabilities, believed to be caused by compression of external structurants.
To address the problem of aeration, a manufacturer may employ a two-step process, where a base composition is made in bulk, de-aerated for a period of time, and then finished by adding additional ingredients. The de-aeration process, however, can cost time and capital, and it is desirable, at least, to keep de-aeration time to a minimum.
De-aeration times may be reduced by producing a low-viscosity base composition and/or product compositions, as lower viscosities are associated with decreased aeration times. However, low-viscosity detergent compositions may be runny and thus perceived by the consumer as cheap and poor performing. Therefore, in order to give the consumer a thicker, more luxurious product experience, the manufacturer may add a rheology modifier after the de-aeration process to increase the viscosity of the final product. However, typical rheology modifiers add expense without providing any performance benefits, such as stain removal, in the end product.
In view of the foregoing, there is a need to provide improved liquid detergent manufacturing processes that allow for efficient de-aeration and improved performance benefits.